What is the best lesson an NCO/Officer has ever taught you?

Trust no one and document everything.

Treat non combat arms like civilian's.

My senior NCO taught me how to function as a part of a complete machine (team). If a team does't work together they all are doomed. The team worked, played and spent time with both each other and their families.

At my first duty station my plt sgt said he was lazy . He explained that he believed in doing a job in a timely matter and correctly the first time so he wouldn't have to go back and do job again.That was March 1985 I still have that work ethnic.

Time management as a professional with much more to do!

Therecis a huge diffetence between being a boss and being a leader. A leader works, educated and guides his team. A good leader will absorb the blame and share the praise for their teams actions. A boss on the other hand just tells others what to do and hogs all the credit.

As a young Airman in a Radio Maintenance shop, my Shop Chief taught me the most efficient way to troubleshoot. He called it "Half Split". Using a block diagram of the system, we started in the middle to see if there was a signal. If not, we did the same from there to the end of the circuit, or vice versa if there was a signal. Only when we localized the issue to a block (module) did we open the pertinent schematic. From there we executed the same process. Very fast, and very efficient. To this day, I still use this technique, and I also teach junior level techs and engineers to use it.

Not the most important career-wise, but as far as leading Soldiers, here is the most important advice I received.. Basically I was a newly promoted CBRN SGT in an Infantry Pathfinder Company just being reactivated that only had about 10 Soldiers total, so at the moment of this lesson, the NCO support channel was 1SG -> Me -> junior enlisted, and I was expected to act like an 11B SGT. I was in charge of getting the 5 junior enlisted ready for step off for an early morning ruck march, and long story short, they didn't have proper gear (about -10 degrees in fort drum). So while the Soldiers were sent back into the Company to get their gear, I got a personal ass chewing from the 1SG, that included these 2 gems that I will probably always remember.. "Your Soldiers either want to BE you, or they're laughing AT you. There is no in between." and "It's call 'Pre-Combat Checks and Pre-Combat Inspections', not 'Pre-Combat Surveys.' SEE and TOUCH the equipment, don't ASK if they have the equipment." When it comes to leading Soldiers, those 2 quotes have served me better than probably anything else I've ever been told.